一种用于自动导引车(AGV)的超声波导航系统

设计了一种用于自动导引车（AGV）的超声波导航系统，介绍了系统的工作原理及结构，并进行了各项导航功能的样车实验，实验数据表明：系统可适应AGV的工作特点，可用于CIMS中固定及自由路径模式的AGV。     

自动导引车模型设计

 自动导引车(AGV)的实现是智能移动机器人研究的重要内容之一． 阐述了自动导引车系统(AGVS)的构
成及工作原理，在此基础上对试验型AGV 模型的功能结构与硬件配置进行了详细的设计，并从软件上得以实现．
通过测试，表明该AGV模型达到了预期效果，为工业应用AGVS的开发提供了参考．     

基于IGPS和麦克纳姆轮的AGV导航控制系统设计

目前常规使用的舵轮和差速轮自动导引车（automated guided vehicle,AGV）的精度和灵活性低,无法满足在大型高端产品装配过程中精确定位和导航的要求。为了进一步提高AGV的导航精度和柔性,提出了一种基于IGPS （indoor global positioning system,室内全球定位系统）和麦克纳姆轮的AGV高精度导航控制系统。首先通过IGPS高精度定位和坐标计算获取IGPS接收器的位置坐标,其次采用车体中心提取算法和坐标转换矩阵实现接收器坐标位置到车体中心坐标的转换,最后通过对全向移动AGV的建模,采用模糊PI控制方法对AGV的路径偏差进行纠正,实现AGV的精确定位和循迹导航。利用Simulink对模糊PI控制和传统PI控制进行仿真分析,结果表明,相对于传统PI控制,模糊PI控制响应速度快,调整曲线更平滑。同时,在基于IGPS的AGV试验平台进行试验,采用激光跟踪仪对AGV重复定位位置进行测量,结果显示定位精度达到±0.2 mm。研究结果对提高AGV的高精度定位能力具有借鉴意义,也为后续可移动机器人加工模式的研究提供参考。     

面向仓库货架的商品智能拣选机器人设计

目的 为降低仓储拣选作业的劳动强度、提高拣选准确率,设计一款可代替人工拣货的拣选机器人。方法 基于PaddlePaddle的PP-ShiTu图像识别系统,实现货架商品的精确识别和种类的快速更新;针对低成本机械臂的视觉抓取问题,提出基于“无标定3D视觉+AGV运动控制”的货架商品抓取引导方法;采用二维码自主导航和智能升降系统实现了货架商品的搬运和立体抓取。结果 实验证明,所设计的拣选机器人实现了货架商品的精确抓取和搬运,测试准确率达到了92.25%。结论 基于该方法构建的智能拣选机器人,可以完成仓库货架商品的拣选和搬运。     

Modelling battery constraints in discrete event automated guided vehicle simulations

This paper investigates a commonly omitted aspect of Automated Guided Vehicle (AGV) simulation—battery modelling. Battery usage is frequently overlooked in simulation for a variety of reasons. First, it is incorrectly believed to have minimal impact on system operation. Second, many analysts do not have an understanding of how batteries power AGVs. Third, battery analysis requires additional input information and varies for different AGV vendors. This paper contains several methods that can be used to account for the impact of various battery usage schemes on AGV simulations. These methods range from general philosophies to detailed model-specific coding examples.     

温湿度对蜂窝纸板静力学性能影响及有限元分析

目的 针对目前定制家具打包运输过程AGV避障方法中,对障碍物信息辨识度较低、难以做到精准避障等问题,提出一种采用视觉传感器基于改进目标检测算法的AGV避障策略。方法 利用Mobilenet模型改进传统SSD目标检测算法,以AGV工作环境数据对训练后的SSD-Mobilenet模型进行迁移学习,结合视觉、超声波等多个模块实现避障原理,搭建以树莓派3B+为控制核心的实验平台进行相关实验研究。结果 实验证明该方法的检测精度达到94%,能够精准辨别障碍物类型;目标检测避障方法的避障通过时间比传统方法减少了15.8%～27.3%。结论 该方法有效提高了AGV避障的准确率与效率,可广泛应用在AGV避障控制中。     

可重构的机器人数据采集与控制系统

本文提出一种新颖可重构的、基于实时Linux的机器人数据采集与控制系统．该系统由PC104计算机和FPGA器件组成,能完成数据采集、传感器数据的管理、底层信息融合以及控制机器人的底层硬件．该集成系统与机器人主控计算机之间的通信采用Modbus协议．可重构数据采集与控制系统作为机器人板载计算机与其他控制器件的接口,能灵活地连接各种传感器和执行器．本系统已应用于保安巡逻机器人,实验结果验证了可重构系统的有效性和实时性．     

An AGV routing policy reflecting the current and future state of semiconductor and LCD production lines

This paper presents an efficient policy for AGV and part routing in semiconductor and LCD production bays using information on the future state of systems where AGVs play a central role in material handling. These highly informative systems maintain a great deal of information on current and near-future status, such as the arrival and operation completion times of parts, thereby enabling a new approach for production shop control. Efficient control of AGVs is vital in semiconductor and LCD plants because AGV systems often limit the total production capacity of these very expensive plants. With the proposed procedure, the cell controller records the future events chronologically and uses this information to determine the destination and source of parts between the parts' operation machine and temporary storage. It is shown by simulation that the new control policy reduces AGV requirements and flow time of parts.     

Comparison of dynamic routeing techniques for automated guided vehicle system

An automated Guided Vehicle (AGV) System with a limited number of vehicles cannot perform all of the transportation requests on demand. When a capacitated AGV system is used, then it is possible for the material handling system to become the bottleneck. There are many factors that affect the efficiency of an AGV system including how vehicles are routed and schedules. This paper presents a new dynamic approach to AGV routing. Simulation is used to study the effectiveness of this approach.     

A New Method of Global Path Planning for AGV

Path planning is important in the research of a mobile robot （MR）. Methods for it have been used in different applications. An automated guided vehicle（ AGV） , which is a kind of MR, is used in a flexible manufacturing system （FMS）. Path planning for it is essential to improve the efficiency of FMS. A new method was proposed with known obstacle space FMS in this paper. FMS is described by the Augmented Pos Matrix of a Machine （ APMM ） and Relative Pos Matrix of Machines （ RPMM）, which is smaller. The optimum path can be obtained according to the probability of the path and the maximal probability path. The suggested algorithm of path planning was good performance through simulation result： simplicity, saving time and reliability.     

面向“货到人”拣选系统的一种随机调度策略

通过“货到人”拣选系统作业流程分析,提出了在分批下发订单任务的情况下的一种随机调度策略。以AGV (automated guided vehicle)完成所有任务的总时间最短为目标函数,以任务分配为决策变量,考虑进行调度时AGV所处的状态以及在完成任务过程中AGV在拣选台的排队等待时间,建立随机调度策略的数学规划模型。利用遗传算法进行求解,通过实例仿真,验证了随机调度策略较调度空闲AGV策略具有更高的拣选效率,同时解决了AGV调度与拣选序列问题,对AGV数量配置具有指导作用。     

全向自动导引车导向机构设计及其运动控制研究

针对麦克纳姆轮加工复杂,运动效率低,承载能力较弱及容易出现振动、打滑等问题,研发了基于轮毂电机的自动导引车（automatic guided vehicle,AGV）全转向导向机构,并根据该导向机构的控制方式--四轮独立驱动和四轮独立转向（4WID-4WIS）的方式,对该全向AGV进行了运动控制研究。首先,构建了该全转向导向机构的运动学模型,并进行了运动学分析,得出不同转向模式下全向AGV转速与转角之间的关系。其次,为消除该全向AGV移动时产生的路径偏差,提出了基于多步预测最优控制和模糊控制的联合路径跟踪控制技术,以提高控制精度和为路径跟踪提供充足的纠偏能力;进行了转向电机和轮毂电机之间的解耦控制,保证了转向电机和轮毂电机具有良好的输入输出响应。最后,通过实车实验验证了该全转向导向机构具有良好的运动效果,能够满足实际工况的要求,可为AGV在工业领域的应用提供一定的参考。     

Deadlock prediction and avoidance based on Petri nets for zone-control automated guided vehicle systems

Deadlock problems of zone-control uni-directional automated guided vehicle (AGV) systems are discussed in this paper. Deadlocks of two types in such AGV systems are first classified from the perspective of shared resources, i.e. guide-path zones and buffers. A special class of Petri nets, attributed Petri nets (APN), is defined and used to represent the current state and to generate future states of zone-control AGV systems. We propose an algorithmic procedure to predict in real time and to avoid deadlocks that are caused by sharing guide-path zones in zone-control AGV systems. The proposed algorithm utilizes the current system state and future predicted states to avoid deadlocks. These states are obtained and generated from the obtained APN. A modular approach is employed to facilitate the construction of APN models of zone-control AGV systems.     

Performance evaluation of tandem and conventional AGV systems using generalized stochastic Petri nets

This paper investigates the different policies and concepts followed in the traffic management of automated guided vehicle (AGV) systems, and develops the controls for automatically eliminating potential vehicle conflicts in an AGV system. The planning of the AGV system is performed in such a way that there are no conflicts or deadlocks for the vehicles using stochastic Petri nets (SPNs). The major effort is devoted to determining the benefits of the tandem AGV control in comparison with the conventional AGV control method. SPNs have been used to model the different designs of flexible manufacturing systems (FMSs) and with different policies for the movement of material, vehicle path control, inventory planning and tool control. The SPN model is solved and the performance of the system can be evaluated. In this study, the effort is directed to model an FMS with two different types of AGV traffic management methods, namely the conventional and tandem AGV control. A SPN program is used which takes the FMS Petri net model as the input and evaluates the different properties of the Petri net. Finally the performance measures are obtained, which helps in evaluating and comparing the two different AGV traffic management methods.     

Navigation method utilizing floor-integrated inductive power supply modules for omnidirectional AGVs

This paper answers the research question: Can the contactless induced energy supply from a novel inductive floor be used to navigate omnidirectional automated guided vehicles (AGVs)?

In contrast to existing systems a novel inductive floor enables AGVs traveling through production without charging breaks. This floor consists of tiles with inductive modules, which supply the AGV with energy. In addition to supplying power to the AGV, the inductive modules are also intended to guide the vehicle through production. To enable such a guidance sensors placed in the AGV measure the induced voltages of the floor. To answer the research question these voltages are calculated with the help of an electromagnetic simulation of the AGV’s travel on the inductive tiles. To estimate the position as well as rotation of the AGV depending on the simulated voltages as inputs a novel algorithm is presented. During the travel the AGV is able to move in arbitrary directions independently of its orientation. To control the omnidrectional AGV consistently without singularities, a transformation in Omni-Curve-Parameters (OCP) is proposed. As simulation case study a four wheeled steering- and velocity controlled AGV is introduced. For the evaluation a novel motion model depending on the input OCP is presented. This model is compared to the estimation of the position to verify the accuracy and the reproducibility of the algorithm.

     

A prototype safety system for new on-the-job training (OJT) in an anthropocentric cell manufacturing system

The anthropocentric cell manufacturing system (ACMS) discussed consists of a skill-based manufacturing scheduling system, a new on-the-job training (New OJT) system and a safety system. The New OJT was developed using e-learning and automated guided vehicle (AGV)-arm robot as a teacher for CNC machine training. Since the machines and the AGV-arm robot are automatic devices, controlled by computer programs, the dangers might arise during training. Therefore, the safety system is required to ensure that a learner will be safe. We propose a prototype of safety system with designed machine-protection in order to protect the learner from dangerous behaviours during a level 1 training of a New OJT in ACMS. The machine-protection focused on protection from danger using image processing with a background subtraction technique and comparison of objects’ position. We also evaluated safety assessments of the learners, consisting of human error probabilities (HEP) and a human error rate (HER). The prototype of this developed safety system showed that the machine-protection certainly raises a warning alarm when the learner rises into dangerous zones during the training. The evaluated safety assessments showed that our designed New OJT training level 1 course performed more efficient safety performance for self-training of the learner.     

A prototype safety system for new on-the-job training (OJT) in an anthropocentric cell manufacturing system

The anthropocentric cell manufacturing system (ACMS) discussed consists of a skill-based manufacturing scheduling system, a new on-the-job training (New OJT) system and a safety system. The New OJT was developed using e-learning and automated guided vehicle (AGV)-arm robot as a teacher for CNC machine training. Since the machines and the AGV-arm robot are automatic devices, controlled by computer programs, the dangers might arise during training. Therefore, the safety system is required to ensure that a learner will be safe. We propose a prototype of safety system with designed machine-protection in order to protect the learner from dangerous behaviours during a level 1 training of a New OJT in ACMS. The machine-protection focused on protection from danger using image processing with a background subtraction technique and comparison of objects' position. We also evaluated safety assessments of the learners, consisting of human error probabilities (HEP) and a human error rate (HER). The prototype of this developed safety system showed that the machine-protection certainly raises a warning alarm when the learner rises into dangerous zones during the training. The evaluated safety assessments showed that our designed New OJT training level 1 course performed more efficient safety performance for self-training of the learner.     

RMS中工件路径网络生成方法

利用图论建立RMS中工件路径网络生成模型。给出设备物理布局生成的3种算法：设备物理规划布局算法、基于二次布置问题(QAP)模型的VMC设备物理布局算法以及已有设备物理布局算法。给出AGV路径网络生成算法、AGV路径网络生成改进算法、可替代路径网络生成算法,包括节点间最短路径寻找子算法、路径网络预处理子算法。算法的输入为表示重构对象节点间距离信息的距离矩阵文件和表示某生产周期多工艺路线的流量文件,输出为优化的路径网络。用Visual C 实现了以上算法,实例测试验证了算法的正确性。     

Scheduling of Automated Guided Vehicles in a Decision Making Hierarchy

Scheduling efforts made without considering the special limitations of the material handling system might lead to infeasible results. An analytical model is proposed, first, to incorporate the automated guided vehicle (AGV) system into the overall decision making hierarchy. A mathematical formulation is developed to include interaction between the AGV module and other modules in the system by considering the restrictions of the material handling system. A micro-opportunistic approach is then proposed to solve the AGV scheduling problem. Finally, the proposed method is compared with a number of dispatching rules.     

Conflict resolution in AGV systems

Currently, conflict-free routing in AGV systems is established by means of one of the following three approaches: (i) the problem elimination through the adoption of a segmented path flow or tandem queue configuration; (ii) the identification of imminent collisions through forward sensing and their aversion through vehicle backtracking and/or rerouting; or (iii) the imposition of zone control and extensive route pre-planning, typically based on deterministic timing of the vehicle traveling and docking stages. Among these three approaches, the segmented path flow-based approach presents the highest robustness to the system stochas-ticities/randomness, but at the cost of restricted vehicle routings and the need for complicated handling operations. This paper proposes an alternative conflict resolution strategy that will ensure robust AGV conflict resolution, while maintaining the operational flexibility provided by free vehicle travel on arbitrarily structured guidepath networks. Specifically, the approach advocated in this paper also employs zone control, but it determines vehicle routes incrementally, one zone at a time. Routing decisions are the result of a sequence of safety and performance considerations, with the former being primarily based on structural/logical rather than timing aspects of the system behavior. The resulting control problem is characterized as the AGV structural control. After defining the notion of AGV structural control, the paper proceeds to the formal characterization and analysis of the problem, and to the development of a structural control policy appropriate for the class of AGV resource allocation systems. The paper concludes with some discussion on the accommodation of emerging AGV operational features in the proposed modeling and analysis framework, and the integration of AGV structural control with the broader control of material-flow among the shop-floor workstations.